HS2 could cost up to £106 billion, according to a widely leaked government-commissioned review yesterday that recommended the rail link should be abandoned north of Birmingham.

An inquiry led by former HS2 Ltd chairman Doug Oakervee reportedly found there is “considerable risk” that the high-speed rail project’s cost will rise by up to 20 per cent.

The report also recommended suspending work on HS2’s rail link to Manchester and abandoning plans for a new high-speed track north of Birmingham.

Mayor of Greater Manchester Andy Burnham described the news as “quite worrying” and warned that using conventional lines in northern England would be a “second-class option.”

He said: “It’s the same old story. London and the south gets whatever it wants, and it’s all about penny-pinching in the north.”

And he warned Prime Minister Boris Johnson that HS2 was the “first big test of your commitment to the north of England.”

He said: “There’s no justification at all for doing one thing between London and Birmingham and doing something different in the north.

“If you’re going to do it, do it properly. Don’t do it by halves.”

A report by current HS2 Ltd chairman Allan Cook, published just four months ago, set out an estimated cost range of between £81bn and £88bn.

The controversial project providing a faster rail link between the capital and the north of England was allocated £56bn in 2015.

A decision on whether to go ahead with the project will be made in “weeks rather than months,” Transport Secretary Grant Shapps said.

TSSA general secretary Manuel Cortes has called for an end to the “dithering and speculation” over the long-awaited project.

He said: “The north of England has spent too long as the poor relation of transport investment. HS2 must go ahead and be built through to Scotland.”